1. Field of the Invention
This invention relates to novel 9,12-bridged ethenoanthracenes containing N in the bridging group, and to methods of making the above compounds.
2. Description of the Prior Art
Unbridged 9,10-ethenoanthracenes are well known in the art, and certain 9,12-bridged ethanoanthracenes have been described (Meek et al., J. Am. Chem. Soc., 74, 761 (1952); ibid, 78, 5413 (1956); ibid, 82, 2566 (1060); Alder and Heimbach, Chem. Ber., 86, 1312 (1953); British Patent 1,266,890). A low yield of a 9,12-bridged ethanoanthracene, ##STR2## was obtained by an intramolecular Diels-Alder reaction (Meek and Dann, J. Org. Chem., 21, 968 (1956)).